Comparison Core Temperature using Electric Blanket Warming between Cover Body and Head with Cover Body in Patients Post Leg Surgery under Spinal Block at Post Anesthesia Care Unit Department of Anesthesiology Chaiyaphum Hospital

Abstract

            Postoperative hypothermia occurs in approximately 70% of patients receiving spinal anesthesia and is associated with significant complications; however, evidence comparing body-only versus body-and-head electric blanket warming remains limited. This study aimed to compare the effectiveness of these two warming methods, including the rate and time to achieve normothermia. A randomized controlled trial was conducted in 62 post-leg-surgery patients with hypothermia, randomly allocated into an intervention group (body-and-head warming) and a control group (body-only warming), 31 per group, using concealed block randomization. Core temperature was measured via tympanic thermometer at 0, 15, 30, 45, and 60 minutes. Data were analyzed using chi-square, independent t-test, repeated measures ANOVA, and Mann-Whitney U test.

            Baseline core temperatures were comparable between groups (34.93 ± 0.43 vs. 34.87 ± 0.49°C,        p = 0.583). The intervention group demonstrated significantly greater temperature increases from minute 15 (35.61 ± 0.45 vs. 35.15 ± 0.36°C, p < 0.001) through minute 60 (36.48 ± 0.28 vs. 35.79 ± 0.30°C, p < 0.001). All patients in the intervention group (100%) achieved normothermia within 60 minutes, compared with 32.3% in the control group (p < 0.001), with a mean time of 30 minutes -48.7% faster than controls (Cohen's d = 2.38, NNT = 1.5).

            Body-and-head electric blanket warming is significantly superior to body-only warming in both statistical and clinical terms, and should be considered standard care for postoperative hypothermia in the post-anesthesia care unit.